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UNITED STATES PUBLIC HEALTH SERVICE 

RUPERT BLUE, Surgeon General 



THE ECONOMY OF GROUND SQUIRREL 
DESTRUCTION 



BY 



J. D. LONG 

Surgeon, United States Public Health Service 



REPRINT No. 238 

FROM THE 

PUBLIC HEALTH REPORTS 

December 11, 1914 




WASHINGTON 

GOVERNMENT PRINTING OFFICE 

1915 

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THE ECONOMY OF GROUND SQUIRREL DESTRUCTION.^ 

By J. D. Long, Surgeon, United States Public Health Service, 

Every farmer of rancher who has had to contend with ground 
squirrels, gophers, or similar pests, has been aware for years that 
these animals have caused great losses each year through damage 
done by eating or destroying growing crops, such as hay, grain, 
fruits, nuts, vegetables, etc.; through damage to young trees, vines, 
and other nursery stock or seedlings; through damage to crops and 
fields that has resulted from flooding of the land due to breaks in 
irrigation ditches and canal banks, such breaks being due, in most 
instances, to burrows made into the banks by ground squirrels or 
gophers. Further, frequent interruptions to railroad traffic, and 
sometimes loss of life, have occurred through cave-ins in railroad 
cuts and washouts in embankments that have had their beginning 
through flood or surface water finding its way through a ground- 
squirrel burrow to a place where damage could result. In addi- 
tion, even though washouts did not occur, subsidence of ties and 
rails took place, due to individual burrows or colonies caving in, 
with resulting increase in maintenance-of-way charges and repairs 
to rolling stock and rails, due to pounding, and on rail ends and 
joints. * 

In California, from July 1, 1913, to November 1, 1914, the Public 
Health Service has caused ground squirrels to be reduced about 90 
per cent over an area of 3,373,146 acres, which includes about 2,000 
miles of railroad right of way. The average cost for labor and 
materials has been about 17.4 cents per acre, and the average infesta- 
tion has been about 6.5 squirrels per acre. From the above it is 
estimated that about 21,925,449 ground squirrels have been destroyed. 
As a result of the above-described operations, it is believed that 
bubonic plague has, for all practical purposes, been eradicated from 
the State of California and that any further danger of its spread 
has been removed. 

During the progress of this work of squirrel destruction so many 
comments were made by farmers, landowners, ranchers, and others 



1 Reprint from the Public Health Reports, vol. 29, No. 50, Dec. 11, 1914. 
7.3398°-15 (3317) 



December 11. 1914 3318 

as to the savings that had resulted, that it was decided to make 
an attempt to collect data and see if any reliable conclusions could 
be drawn from the replies sent in. To this end a circular letter was 
addressed to supervising inspectors in charge of the various counties, 
accompanied by a supply of blank forms to be filled out by farmers, 
ranchers, and others. The circular letter and blank form are given 
below : 

[Circular letter.] 

United States Public Health Service, 

111 New Montgomery Street, 
San Francisco, Cal., 8eptemJ}er 2^, 1914. 
To Supervising Inspectors: 

There are foi*warded yon, under separate cover, 250 blank forms, which yon 
are directed to apportion between yourself and your field inspectors. 

These blanks are to be taken to those landowners in the various districts 
who have effected practical squirrel destruction, with the request that for the 
good of the work and in the interest of its future continuance the questions on 
the blanks be filled out as accurately as may be possible and the blanks signed. 

All the information furnished will be considered as confidential as far as 
individuals are concerned, and only the total I'esults of the investigation in each 
county will be used. Names of indiindnals will not be given out except hy 
consent, as indicated on the blanks. 

Signature is desired only as evidence of the authenticity of the report. 
Instruct your field inspectors to render such assistance in filling out the blanks 
as may seem necessary or desirable, in order that the information obtained may 
be as nearly accurate as possible. 

Supervising inspectors are directed to forward all complete blanks to head- 
quarters as soon as they are received, in order that the compilation of th© 
information may be proceeded with at once. 

(Signed) J. D. Long, 

Surgeon in Charge Field Operations and Laboratory. 



[Blank fonii.J 

California, 

I , 191—. 

It is requested that landowners and others supply the following Information 
In order that the economic benefits of squirrel destruction may be more clearly 
known and in order that actual data on this subject may be compiled. 

Give figures as nearly accurate as possible on property controlled by you. 

Location of property: T R sec or grant. 

Total acres 

Number of acres under cultivation 

Number of acres in pasture 

Number of acres wooded 

land under cultivation. 

Kind of crop 

Method used to destroy squirrels 



3319 December 11, 1014 

Amount of money expended in squirrel destruction (labor and material) $ 

Estimated increase in crops due to the destruction of squirrels, as compared to 

previous years (in tons or pounds of crops) 

What was the increase in crop worth? 

Has your land increased in value, due to the destruction of ground squirrels 

(if so, how much per acre)? 

PASTURE LAND. 

Method used to destroy squirrels 

Amount of money expended in squirrel destruction (labor and material) $ 

How much has your pasture land increased in value, due to the destruction of 

ground squirrels? 

Can you pasture more stock on your land, now that your squirrels are destroyed, 

than you could before? 

If so, how many head? 

Give the acreage of the pasture land on which your figures are based 



Under this heading give any other benefits that may have resulted from the 
destruction of squirrels, such as saving on repairs to canals or irrigation-ditch 
banks, savings on young trees or nursery stock, or on grain or other products 
that may have been stored for future use. 



My name may be referred to in connection with this report, if deemed neces- 
sary. 

(If it is desired that the name of the signer Is not to be referred to, cross out 
the preceding sentence.) 

(Sign here.) 

From September 24, 1914, to November 1, 1914, 497 replies had 
been received. The information given had apparently been care- 
fully compiled, and is believed to be as accurate as can be obtained. 

Onl}' the increase in crop is taken into consideration, this increase 
being figured on the basis of the average crop for preceding years, 
when ground squirrels veere present and taking their annual toll. 

The 497 replies received represent a total area of 321,233 acres; 
the total sum reported as expended for squirrel destruction over this 
area amounted to $36,091.85, or an average of 11.2 cents per acre; 
the value of the savings realized over this area from the destruction 
of ground squirrels amounted to $109,301.50, or an average saving 
of 34 cents per acre, which represents a return of 303.5 per cent in 
the first year. 

To illustrate the savings on each particular type of crop or in- 
dustry, the following figures, taken from the returns as compiled, 
are given : 



December 11, 1914 3320 

Cultivated Lands. 

171 persons saved 1,746 tons of hay value— $15, 890. 50 

249 persons saved 2,415.4 tons of grain do 50, 144. 50 

76 persons saved 208.5 tons of fruits do 5, 338. 50 

15 persons saved 18,395 pounds of nuts do 1,882.00 

36 persons saved 287 tons of vegetables do 4,026.00 

Three hundred and seventy of the above persons estimated that 
their land had increased in vahie $2.74 per acre as a direct result of 
squirrel destruction. (This figure of $2.74 per acre increase in value 
has not been included in the total savings of $109,301.50 given above.) 

Pasture Lands. 

One hundred and fifty-two persons reported that 2,163 more head 
of cattle could be pastured on 150,845 acres of pasture land than 
could be pastured before squirrels were destroyed, or 1 additional 
horse or cow to each 69.7 acres of pasture. This saving alone, esti- 
mated at the usual figure of $1 per month per head, represents a 
saving of $25,976. 

One hundred and sixty-eight persons estimated that their pasture 
land had increased in value $1.17 per acre as a direct result of squirrel 
destruction. (This figure of $1.17 per acre has not been included in 
the total savings of $109,301.50 previously given.) 

Various Savings. 

Twenty-one persons reported savings of $2,331 in repairs to irri- 
gation canal banks, but made no estimate as to losses due to flooding 
in previous years. Average saving per person, $111. 

Thirty-six persons reported "great savings on repairs to ditch 
and canal banks," but made no estimate of the amount saved. 

Twenty-two persons reported savings of $2,188 on young trees, an 
average of $99 per person. 

Nine persons reported savings of $1,525 on grain and other prod- 
ucts that were kept in storage in granaries, etc.; average saving, 
$169.44 per person. 

The great majority, under the heading of remarks, expressed their 
satisfaction with the results obtained and hoped that the work would 
be continued until ground squirrels were entirely eliminated. 

It is thoroughly realized by all interested parties that, to obtain 
good and satisfactory results of a permanent nature in work of this 
character, the Federal, State, and county governments and the people 
themselves must work in complete and harmonious cooperation 
through some such organization as has been at work during the past 
year. 



3321 December 11, 1914 

Summary. 

Replies received 497 

Amount expended in squirrel destruction on 321,233 acres $36,091.85 

Amount expended per person $72.61 

Amount saved as a direct result of squirrel destruction $109,301.50 

Amount saved per person $201. 81 



ADDITIONAL COPIES 

OF TmS PUBLICATION MAY BE PROCtTRED FROM 

THE Sin-ERINTENDENT OF DOCUMENTS 

GOVERNMENT PRINTING OFFICE 

WASUINGTON, D. C. 

AT 

5 CENTS PER COPT 



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